SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a21845d7634541bf88e7db6d615991aa09001712f2cd1fc637cb678bbaaa6fd5' 
  AND token = 'Y8m33LZeIzH20uZUTd71orE98KH1zzEePjbsYz0zpto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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