SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b4fefd063e9bc479ea00bab8291b56fce2f623f5bcabc4fd0cb0ae301350f0f0' 
  AND token = 'aNg0QNp3kE5NpZf2d6y8gK+QUSIEr9ETQJvD0uQ2Ssc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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