SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '776e011bc15f94ae08f714efc0e3524592766670d2b4a4a428e6fe7f5d94a8b2' 
  AND token = '1I1n5IpM1S9Ve43uKzxFtjghs+G/Bv/vQxEsT1yNuZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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