SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c696e5b1c2b590e57fa3e3b3544940fa4e69ec540556651220a6e86d30fd855' 
  AND token = 'HpAPMJSgEbHF5ZJTyjMi43kpwR0fOUHKCth3x8saZDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}