SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad58b0041c3cb80299126fc4c319ef24a5d3944bd3f9745531f89b949727da24' 
  AND token = 'RR+6Dt+zWx1dj//DQYzKPHgbiXwO6mC+ykPX/NgM0O0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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