SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5f7329b9825f010bef63ef54ce3f270370aaac164630c2d75917cce79d19ece' 
  AND token = 'odxp+vytwHLU2dMTjiQHO+2AimqaEWLOFls1POIcKEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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