SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f885ab3d82ece514bfa5bbdd14e97f90881845bdac30dc4512212f73c11e1c11' 
  AND token = 'F58fr5EL52jSjpfPIOinrj4pkN/Xbc3kFpVI9y1D3aQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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