SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5547a66cfd112cec85a1d7f46ac264fd6f189416e338b9f2fe2823998950e132' 
  AND token = 'Xo+EncnmV9hOQfyW6K+d7tFSkz2HBMOjoL0px1rNhaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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