SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82755b5bffdd4b38416bb27dd9ca71d82e2a0b19097d335d41109f54312d5ea1' 
  AND token = 'vAK6fBauyKkrbRlOYA7Zro+gMTn/wuV16CeKjLpUcaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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