SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe3e4615f0f390227cf4c7335a00655257a29d2816f6694da65136da7e82c04b' 
  AND token = 'L6Dz+lVkKnt6chpoEF6kqIQqdL/xoInKEhJwvDgkrVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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