SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0313e128342f0417ae8b556b504fab77ce1e998545e9a33fa84cc36f516208b' 
  AND token = 'qA/upouOpIfSGvr4iJjPIN8Vbc+p2KfKBlJNaKvX1GM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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