SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a4f546cbfc9dcd2518d57ee44dfa8069b14a6b149012d8901a37ae124138e53e' 
  AND token = 'vZmFGqkh/h0BYrdaDM0mEemjS9N2J3DjPMBWh89zbHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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