SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba945b6529dc1424f5030b359f0ff3cdd408b1f90ad916f5786a1fe7b256e01f' 
  AND token = 'ZQL0SJbYCdQJweRH28dRwtCVZAyYmx2qm5bl74lw+yA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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