SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '29b3880098c18c123f208a58d139986a5ee46c9354ec6d6fd02e98f6d45ab636' 
  AND token = '3rjiFr9CwMFsCQ6CzfmC2/cUJ+LMPghqjav6px3gxU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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