SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52aaca5bdfc01cae04d285ed987eea55b35dc28da1c0b0e5c758937da5bdd248' 
  AND token = 'FCu4eupJ0T0hUdJuUHhHqRErGutc7Cx2nxEq8cMu6H8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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