SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fbd8d2e8258f7c8a49158c9b126f5d1f07913345d461dc38da72eea7a0907df' 
  AND token = 'zWYL9Or+uUcq/RI3yrzUnQ46ZRqYOhanjlbPP7T3id0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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