SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4bef4243c44245bcb12f2ae3637e1b69ada7ee7cb932dbdd986c895b2aacc99' 
  AND token = 'D3+vAnEUEI0oXuitkqQsFzCCj2O03FCeDlRK1S85BzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}