SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66d0c1c96874eb08ae59fb158d0d42058cc4c90473571da2a5d14595f6b905c2' 
  AND token = 'tQQb8BSqcd90joMLcl1jrHh6O03jvRDWkUzWjzFJ+pE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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