SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '905b293fc86566269de3119c511f090626a761d1346f1f12c28443b6a3e6fa47' 
  AND token = 'Z+P0XnYPMjeRBj+u723ztxNXHcZL5+ykWbnWqJcNGQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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