SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8877cb51146b344ea2d2ca063d4576d4d53225a8d7692874ed0c2a287018370d' 
  AND token = 'pS19dvOGZZ5QEP0vXpGI/UePIQaxaySEm1ki4Ztd/VA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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