SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3845da1bed6b3cb1119570894b37b4792dc769b7f4bdbf300edf3547c853db59' 
  AND token = 'cau6ZakOAuQsmsJew1szrh/6X/NoVyb6RS/OieeqHbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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