SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '966713e18695ee46007e158cfd3f85486acbed229d3a17423a085f483f15ec0e' 
  AND token = 'BqLGvbPzflFnN0xazEVM9CIKmzx3KR2LRQkvj7/B9b8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}