SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ae5714022346ce1cf004dfa77aaab3833dee831e93ea416c07c518cd9789caa' 
  AND token = 'cN0Crjr3Z2e7wIwruP9IYU4BKDrNTzqigW2nD2YYUYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}