SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c8a960de64ab866f20fa6c8aead9aa0a38388ec482fde40cfe6dff11b858b4c' 
  AND token = 'GgCFfYkBj06uV/d0mcie2blBklmIf3ZFrkiA0gmbHWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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