SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da3ff1413dc1831634fdf379da235eb6c44224ce555b398e19eab51f90feb8a7' 
  AND token = 'GJnFMfIn1ueQ0zuZ9svnMnVngcpDScl9mHO/e9Tv9CE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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