SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7b3fbd3b8a86dd996254f7e985fbe2aa13b2b5a0e5c2a55194925b3b0e1165a' 
  AND token = '0R2+ekb8KgFlIEke3i0lArx/dZV6JMpCIpQJUg2MXfc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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