SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1f4d9f3620ce0b8956e285da2e4d0f8a6bcee5e68cf9df0304205e00c292e19' 
  AND token = 'jo2caTFinfPhpfhFFIr1V/WERsxGZFbMgGxaSJTc4ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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