SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c6d084951e5086d01ff34444649717bac694bf351832cab4114e1fa7a8ecb3e' 
  AND token = 'gYAtqpBZMnR4s5kjGNu6HEl3dLs0s6RbRwYSoQMcgHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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