SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2da9db6a526880ee4d970c5cf21690343d7dd6d3904316241d30c6697553fd8f' 
  AND token = 'enbl0UzMgOLQVnGCjst4GuWitnAtzjKKVKnQOr1iQwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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