SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd8629c57d4c6ff1e794b2eff678cf5bf1c69841fbd04a39fa786299c32b38343' 
  AND token = 'unLiqSvWV/0sQpyi6vJ2FX+o4iub/fPGjAcfEu9LXXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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