SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c64ff167de8a20fef3788f2ba5138921a56d03d39f90d9775da964d2a853d6a5' 
  AND token = 'b/HAZl+d41j7y6jgLKsBJJASFvM1fR3RzuD835VHI94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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