SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3c7aad6e789e5e847b22bbeab52c148bee14cfe1e8dcdf4052e37b2d2215a5b' 
  AND token = 'NFYpFhf4Nl7W4eLoAURhqTU8lwaLY2x8y1JfASc2YiY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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