SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bd19c092ac14919b5cfd6b75067f5791f77d0d14143f56c3e85fc5dcabfa100' 
  AND token = 'PBdfkrxeX1je+aC5cYzCgcz72AeSMGuJScPvCmLebx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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