SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85c9b8dfaf51ddf3f378040c4e74d5ba16203015fa96fb437dab0693f327936c' 
  AND token = 'oS6IZUqgHUi/K5VHrbei27fh0aoFoQ/mDJuK9dKrhUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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